Many people are in all types of hobbies such as model railroading, model ship building, model car building, model airplane building, all types of military modeling, and many types of crafts. All of these people have one thing in common: they all try to achieve the art of building scale models in an exact, beautiful, and down to the last detail manner. To do this, they spend many tedious hours of painstaking, eye-straining work.
In a particular example, scale model railroad building includes reproduction of steam locomotives from stock sheet brass and structures such as buildings and towers of heavy card stock down to paper. Modeling in brass requires a vise, ruler, tin snips, file, jewelers saw, and the modelers eyesight. When modeling in a medium other than metal, an Exacto.RTM. knife or saw is used. The prior art related to cutting and handling of materials has changed very little in the past 50 years.
Hobbyists currently use scissors, razor blades, and/or specialty knives such as an Exacto.RTM. knife for cutting various kinds of sheet material in performing their hobby. The accuracy of any cut made using these prior art cutting instruments depends on the hobbyist's ability to measure properly and evenly cut along a particular line using a straight edge such as a ruler as a guide.
Various materials require the use of different types of scissors such as scissors for cutting paper, card stock, flexible and rigid plastic material, and metal sheets. The metal sheets require the use of metal cutters generally known as tin snips. Various types of razor or knife blades are used to cut sheets of card stock, cork, and various types of plastic materials such as Styrene.
Difficulty is generally encountered when cutting sheet stock having a thickness of up to about 1/16th to 1/8th of an inch. For example, a thicker piece of Styrene may require several passes of a blade along the cutting line to make the desired cut. When the blade slips out of the original cut either the sheet is ruined or an uneven edge on the cut piece is produced. Neither condition is desirable to a hobbyist.
When using scissors or blades to cut very thin sections from sheets of metal material such as bronze, brass, aluminum, tin, and the like, often the thinly cut segments curl up onto themselves. When this occurs, it is extremely difficult and in some cases impossible to use the curled segments for constructing a model. This is particularly true, for example, when modeling such things as model railroad engines and cars.
Because of such problems, many modelers use pre-cut kits that simply require assembly. Those who desire to build models from "scratch", however, have particular difficulty in cutting such thin pieces from a larger sheet of stock material often resulting in significant frustration.
When breakage or inaccurate and incomplete cuts occur, the sheet of material may become scrap without its original edges and corners. Once the original straight edges and square corners are gone, the equally important aspect of accurate measuring before cutting the sheet stock is precluded causing the sheet to be scrapped.
The existing method used by modelers for measuring and cutting segments from sheet stock is laborious. First, they accurately measure the width to be cut from a sheet stock and mark the sheet surface along a straight edge to designate the cutting line. With one hand, the straight edge is pressed against the sheet while the other hand guides a cutting blade along the line and against the straight edge. The modeler must hold the straight edge tightly against the sheet stock and carefully apply cutting pressure to the blade. If the straight edge moves or for some reason the cutting blade deviates from the cutting line, the modeler may have to make another cut from the same or another sheet of material.
Because the current cutting and measuring process in the hobby industry is most painstaking, a person's ability to model is completely dependent on the person's skill in manually holding the straight edge and the sheet being cut against a support surface while carefully and accurately guiding a cutting blade along a manually measured cut line.
Known cutting and measuring devices are shown in U.S. Pat. Nos. 219,681; 954,052; 957,747; 1,416,800; 1,419,789; 1,681,739; 2,071,402; 2,130,818; 2,488,610; 3,176,568; 3,240,094; 3,376,728; 3,491,643; 3,803,968; 4,204,450; 4,581,825; 4,936,177; and 5,105,703. None of these prior art devices are useful for effecting the degree of accuracy and precision required in modeling detailed structures.
Furthermore, none of the disclosed assemblies shows a hand-turned lever crank mounted to move a cutting blade up and down and enables work to be cut at either side of a cutting blade using abutment means on opposing sides of the cutting blade. None of the prior art references show a screw turned with a hand-manipulated lever mechanism. And they disclose no device whereby a cutting edge is displaced a spaced distance from the center of a rotatable drive screw.